An operating system (OS) is a computer program that manages and controls computer hardware and software resources, exists between underlying hardware and a user, and is a bridge for communication between the underlying hardware and the user. The user may enter a command on a user interface of the operating system. The operating system interprets the command and drives a hardware device to implement a requirement of the user. A response time of hardware access is a most important indicator for evaluating performance of an operating system.
In an existing operating system, the operating system provides an interface for a hardware physical resource in a kernel, and an upper layer is encapsulated into an application programming interface (API) to be called by a user program.
Therefore, in the existing operating system, when the user program calls a related API to access the hardware resource, the system needs to trap into the kernel, and the system switches between user space and a kernel mode for multiple times. Such frequent switching increases overheads of the system, and causes decrease in processing efficiency of the system.